September weather forecast
El Cajon, CA

September denotes a gentle shift from summer towards fall. The weather sees a reduction in temperature, with days becoming slightly cooler, providing respite from the summer heat. While the sun continues to bathe the city in its warmth, the declining daylight hours signal the onset of the autumn season. Despite the cooling temperatures, beach activities and water sports continue to be popular due to the warm ocean water. The temperature fluctuations reduce slightly, varying between 82.6°F (28.1°C) to 63.9°F (17.7°C), indicating the impending transition to cooler weather.

Temperature

El Cajon records an average high-temperature of a still moderately hot 82.6°F (28.1°C) as September arrives, nearly mirroring the previous month's climate. Throughout the month of September, the nighttime temperature dips to an average of 63.9°F (17.7°C).

Heat index

For most parts of September, the heat index is calculated to be 84.2°F (29°C). Prolonged exposure and physical activity might induce exhaustion, potentially causing heat cramps.
The heat index's values are generally associated with conditions in shade and light breezes. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. Awareness of direct sun exposure is crucial as it has the potential to heighten the weather's effects, pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.

Humidity

In September, the average relative humidity in El Cajon, California, is 59%.

Rainfall

In El Cajon, during September, the rain falls for 4.1 days and regularly aggregates up to 0.31" (8mm) of precipitation. Throughout the year, in El Cajon, there are 56.1 rainfall days, and 8.27" (210mm) of precipitation is accumulated.

Daylight

In September, the average length of the day is 12h and 22min.
On the first day of September, sunrise is at 6:23 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:33 pm PDT.

Sunshine

In September, the average sunshine is 10.4h.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: A maximum daily UV index of 6 during September morphs into the following directions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.